In my opinion it depends on how to use the platform. If you like to give more exposure to your business you can use Facebook, where you can create a page, that allows you to publish photos of your service/company or what people you want them to know. If you want to directly approach other people for business purposes, Twitter is the one you'll need.
well as per my opinion facebook is the best beneficial website because let it be a student let it be a professional all are present on facebook and that is what makes facebook a very huge potential market for the online marketing and that is why it is usually targeted by all the internet marketing specialists.
It help you to connect more people at a time socially and you can more friends personally as well as officially .Social Media is also provides a good platform to your business and is beneficial to promote your brand.
Facebook, Google Plus, Twitter, Pinterest, Tumblr, Linkedin, Youtube, Digg, Myspace are the best social networking sites. All these SMO can help you most for Increasing website performance on internet. This strategy is the Sub part of SEO. We can use this strategy for permuting our website.